Bulgarian prosecutors said they were investigating an international money laundering scheme allegedly involving huge sums of Russian cash.

Apparently, the money was channeled through the company, and was deposited into Bulgarian banks. About 500 million euro were transferred to a financial company in Estonia, where the cash was withdrawn.

Most of the money belonged to organized crime groups from St. Petersburg, which used the channel to launder it, to evade taxes, and to execute illegal financial operations.

It seems to be included in the crimes, the powerful Tambov gang. The latter's name is usually connected with protection rackets, drug trafficking and other illegal activities.

Asked about a newspaper report which confirms this information, the prosecutors' spokeswoman Stelyana Kozhuharova said there are probes to confirm that.

But she also refused to provide further details, because the "very confidential" nature of the investigation.

The investigation, which is going on in Bulgaria, is secret. Two persons were detained in Bulgaria on May 23, 2008, for this case -- Elizabet Elena Von Messing and Dmitriy Abramkin. Von Messing is a Russian with Finnish citizenship, and Abramkin had acted as her proxy. The court hearings on the detention of the two Russians are not open to the public.

About a billion euros of dirty Russian money were first transferred to a real estate and financial services company in Bulgaria, called Optima Ca.

That firm then wired half of the money to the Estonian financial house AS Tavid, which sent the cash back to Russia.

The rest of the money was transferred to accounts in Cyprus, Dubai, Hong Kong and other countries, according to the newspaper.

Von Messing was the owner and manager of the "Optima Ka Single Member Ltd.," whose bank accounts were used to channel over one billion euro of money transfers coming from Russia. The firm's head office is located in downtown Sofia, but is currently sealed.

She was convicted of tax fraud in Finland more than 10 years ago.She also was accused to had once been married to a member of the Saint Petersburg mafia, but it was immediately denied, she said that her first husband worked for the Russian intelligence services

The Bulgarian prosecutors have charged Von Messing and Abramkin with money laundering and illegal financial transactions of about 500 million euro by the Bulgarian prosecutors.